Inset high intensity light and cooling means therefor



June 23, 1970 w. c. DALEY ErAL 3,517,181

INSET HIGH INTENSITY LIGHT AND COOLING MEANS THEREFOR Filed July 27. 1967 K 's wn N 2 Sheets-Sheet 1 www@ INVENTORS ATTORNEYS June 23, 1970 w. c. DALEY ErAL 3,517,181

INSET HIGH INTENSITY LIGHT AND COOLING MEANS THEREFR Filed July 27, 1967 2 Smets-sheet 2 M I A' s 520 'M110 F/G- 6 -400 fnted Patent Office 3,517,181 Patented June 23 1970 U.S. Cl. 240-1.2 6 Claims ABSTRACT OF THE DISCLOSURE An hermetically sealed, high intensity, inset runway light having a filament-type lamp sealed in a quartz envelope with a molded ceramic composition potted around the lamp seals to align the filament with lamp holders surrounding the seals and accommodate for misalignments between the filament and the envelope inherently resulting during the manufacture of the lamps wherein heat conducting paths, such as metal crclets of adjustable diameter, are embedded in ceramic compound and contact the seals and the holders to transmit heat from the seals. A second embodiment utilizes the crclets embedded in the ceramic positioning compound and a refrigerant radiator in tandem to conduct heat to the housing for the fixture. A third embodiment utilizes a refrigerant radiator which directly engages the lamp seals and conducts heat to the housing of the fixture.

This invention pertains to roadway inset lights such as are commonly used for airport runway markers, particularly the hermetically sealed type.

Modern inset runway lights are required to be of high intensity to provide the necessary illumination for safety purposes. The lamps for such lights are of the filament type wherein the filament is encased in a quartz envelope which is flattened at its ends to seal the envelope to the filament leads for the lamp. Present manufacturing processes for forming the seals do not result in lamps wherein the filament is supported concentrically within the envelope. .Since the filament must be precisely positioned in runway light fixtures to focus and direct the beam of light as required, it is necessary to ensure that the positioning of the filament in the light fixture is unchanged when replacement lamps are installed.

James F. Angiers pending United States patent application, Ser. No. 539,235, filed on Jan. 31, 1966, meets this requirement by providing for the alignment of the filament of each lamp with its special lamp holders molding a ceramic compound around the seals to support the lamp holders in fixed position relative to the filaments of each of the lamps. Sincethe temperature rise of the lamp seals is the factor limiting the amount of illumination which may be obtained, and the ceramic compound serves to impede the dissipation of heat from the seals, the required alignment of the filaments limits the size of lamp which may be used.

The present invention solves the heat dissipation problem referred to above by transferring heat from the quartz end seals, while accommodating the alignment of the filaments as set forth in the Angier application.

An object of this invention is to provide a new and improved marker light which can be installed in surfaces utilized by wheel vehicles.

Another object of this invention is to provide a runway inset marker light having a precision aligned filament wherein the heat is efiiciently transferred from the lamp envelope.

Another object of this invention is to provide a filament-type runway inset marker light having a precision aligned filament utilizing both mechanical and fluid heat dissipation paths to convey lamp-generated heat away from the lamp envelope.

Another object of this invention is to provide a filamenttype replacement lamp assembly having a precision aligned filament for a runway inset marker light fixture wherein the heat is efficiently transferred from the lamp envelope.

Another object of this invention is to provide a filament-type replacement lamp assembly for a runway inset marker light fixture incorporating both mechanical and fluid heat dissipation paths to dissipate heat generated in the lamp envelope.

Other objects become apparent in the specification that follows:

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a cross-section view through the centerline of an installed light fixture containing a lamp assembly utilizing one embodiment of the invention;

FIG. 2 is an end view taken along the line 2-2 of FIG. l;

FIG. 3 is an enlarged fragmentary longitudinal elevation, in section and partly broken away, of a light fixture illustrating another embodiment of the invention;

FIG. 4 is an enlarged end section view of the device of FIG. 3;

FIG. 5 is an enlarged fragmentary longitudinal elevation, in section, of another embodiment of the invention; and

FIG. 6 is an enlarged end section view taken along the line 6-6 of FIG. 5.

In the drawings, FIG. 1 illustrates an hermetically sealed lamp fixture generally indicated by 8, appropriate for airport runway inset installation, as shown, and comprising a waterproof casing 10 permanently embedded in a runway, a base ring or lamp support means 12 hermetically sealed to the casing 10 by means of an O-ring 16 and bolts as shown without designation, and an optical assembly shown generally at '62. The optical assembly 62 is sealed hermetically to the base ring 12 through cover 14 by an O-ring 18. The cover 14 is removably fixed to the -base ring 12 by an appropriate means such as bolts, not shown, and is lprovided with suitable lenses, not shown, for passing light generated in the fixture.

Metal cover 14 blends with the base ring 12 to form a low profile fixture top portion designed to bear stresses of aircraft rolling over the same. Removal of this cover permits the optical assembly 62 to be lifted out for ready inspection and maintenance.

`Optical assembly 62 includes a quartz lamp envelope 20 and la filament 22 having leads 24 connected to thermally and electrically conductive envelope holders 26.

The holders are electrically and removably connected with terminals 28 through positioning springs 27, which in turn are connected to supply lines 34 by leads 30` and lead-thoughs 32.

According to one aspect of this invention and as shown by FIGS. 1 and 2, metal annuluses or circlets 36 are embedded in the ceramic compound 38 between the end seals 21 and the holders 26 to form heat conveying paths from the seals 21 to the thermally conductive holders 26. The circlets are preferably rolled from strip stock so as to have adjustable diameters and thus accommodate themselves to the shifting of the end seals during procedures for aligning filament 22 with the holders 26 as set forth in the pending Angier application and to each remain in contact -wit'h the lassociated end seal 21 and the holder 26. The circlets thus provide efficient, multiple paths that transmit heat from each end seal 21 through the ceramic compound 38 to the broad areas of the adjacent thermally conductive holders which provide enlarged surfaces to dissipate the heat.

Another embodiment of the invention is shown in FIGS. 3 and 4, employing a combination of the circlets 36 embedded in the ceramic compound 38 with refrigerant radiator means 64 in tandem or piggyback fashion. The refrigerant radiator means comprises a seal cooler fitted atop the lamp holders 26. In this embodiment, leads 24 contact the terminals 28 directly rather than through the positioning springs 27 as in the embodiment of FIGS. l and 2. The holders 26 are retained in position as before, by the springs 27, but insulating pads 29 are installed on the holders to isolate them from the springs and from the leads 24.

The cooler 64 comprises evaporation chambers 66 having wall structure 40 containing refrigerant 42 and communicating with common condensing chamber 68 having wall structure 44, the top of which is in intimate heat transfer contact with cover 14. The evaporation chambers 66 are shown placed on the holders 26 directly over the circlets 36. Heat from the end seals 21 passes through the ceramic compound 38 by means of the circlets 36, thence to the holders 26 and then on the refrigerant 42 which absorbs the heat and rises as vapor into condensing chamber 68 -where it is cooled, as the heat passes through the top wall 44 thereof and the cover 14 and out to the atmosphere to condense the refrigerant which drops back into the evaporation chambers 66 for recycling. If desired, and as shown, the seal cooler 64 can be removably mounted to the lamp holders 26 by any suitable devices such as the retainer springs 46.

Another embodiment of the invention is illustrated by FIGS. and 6. As shown, the evaporation chambers 660 of this seal cooler 640 directly engage the end seals 21 of the lamp 20. As heat passes from the end seals 21 to the cooler 640, refrigerant 420 is turned into vapor in the chambers 660 provided by the enlarged bottom end of thin-Walled percolators 480. The refrigerant vapor rises quickly in the percolators 480 and spills out over the top thereof into contact with the top walls 440 of the condensing chambers 680' whence it is cooled, as the heat passes through the top Walls thereof and by conduction into the cover 14 in intimate heat transfer contact with the said top walls, and out to the atmosphere, to condense the refrigerant which returns to the evaporation chambers 660 via, for example, apertures 500 for recycling. Sloping floors 540 of the condensing chambers 680 facilitate refrigerant drain-back, and cooling fins 520 expedite dissipation of heat from the chambers 680 to enhance the cycling of refrigerant and thus the dissipation of heat from the end seals 21. Preferably, and as shown, the cooler 640 can be removably mounted on the end seals. 21 by retainer springs 460'. The separate chambers 680 maintain a balanced quantity of refrigerant therewithin, although one chamber 680 serving both chambers 660 could be used.

From the foregoing, it is apparent that the use of this invention will result in greater light output for a light fixture of a given size. For example, where the embodiment of FIGS. 5 and 6 is utilized, a lamp having 40% higher output can be used in the same size housing. Thus, in the quartzline lamps a 60 watt lamp now can be utilized in a fixture sized to accommodate a 45 watt lamp. By the same token, and selecting a 200 watt light fixture as an example, the xture can be reduced in size by 2/3 and still dissipate the heat generated by a 200 watt lamp.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above-described will become readily apparent without departure from the spirit and scope of the invention. For example, it Will be apparent that a percolator can be utilized in the embodiment of FIGS. 3 and 4. Accordingly, the invention is not limited to the exact embodiments shown and the scope of the invention is defined in the appended claims.

We claim:

1. In an hermetically sealed high intensity light fixture suitable for installation in a roadway comprising a casing, and an optical assembly in the casing, said optical assembly including a filament-type lamp in an envelope having at least one end seal, lamp holder means confining the end seal in moldable setting-type compound and supporting the filament of the lamp in precise alignment with the lamp holder means, the improvement wherein metal annuluses are positioned within the compound to bear against the end seal and the lamp holder means to provide a heat conductive path therebetween.

2. In an hermetically sealed high intensity light fixture suitable for installation in a roadway comprising a casing, and an optical assembly in the casing, said optical assembly including a filament-type lamp in an envelope having at least one end seal, lamp holder means confining the end seal in moldable setting-type compound and supporting the filament of the lamp in precise alignment with the lamp holder means, and a metal cover for the fixture, the improvement wherein means engaging said end seal and said lamp holder means and providing a heat conductive path therebetween is provided within the setting-type compound, said engaging means comprising mechanical means providing a heat path from the end seal through the compound to the lamp holder means, and fluid cooling means providing a heat path from the lamp holder means to the cover.

3. A lighting device as claimed in claim 2 in which the mechanical means are metal annuluses positionable within the compound to bear against the end seal and the lamp holder means, and the fluid cooling means include refrigerant confining evaporation and condensation chambers thermally connecting the lamp holder means and metal cover.

4. For use in an hermetically sealed high intensity light fixture suitable for installation in a roadway and including a casing embedded in the roadway, a replacement optical assembly for the fixture including a filament-type lamp in an envelope having at least one end seal, and lamp holder means confining the end seal in moldable settingtype compound and supporting the lamp filament in precise alignment with the lamp holder means, the improvement wherein mechanical means of variable dimensions and high thermal conductivity within the setting-type compound bear against said end seal and said lamp holder means and provide a heat conductive path to transfer lamp-generated heat away from the envelope.

5. A replacement lamp assembly as claimed in claim y4 in which the lamp holder means is metal and metal annuluses are the heat transfer means positioned within the compound to bear against the end seal and the lamp holder means, thus transferring heat from the end seal through the compound to the lamp holder means.

6. A replacement lamp assembly as claimed in claim 5 including a metal cover for the fixture, in which refrigerant confining interconnected evaporation and condensation chambers thermally connect the metal lamp holder 5 6 means and the xture cover to transfer heat from the lamp 3,349,233 10/ 1967 Angier 24U-1.2 holder means to the xture cover. 3,390,373 6/ 1968 Ruston 240-47 XR References Cited :JOHN M. HORAN, Pri-mary Examiner UNITED STATES PATENTS 5 D. s. STALLARD, Assistant Examiner 2,295,031 9/ 1942 Davis 24U-47 XR 3,112,890 12/1963 Snelling 24o-47' XR U-S- CL X-R- 3,250,907 5/1966 Keck et a1. 24m-1.2 24o-47 

